Conventionally, in a fabrication of a device, a liquid crystal or the like, there has been a problem that an object to be processed is contaminated due to particles produced in the fabrication process thereof. Therefore, reduction of the particles has been required.
For example, as described in FIG. 5, a dry etching device, which is a processing apparatus for an object to be processed, includes a vacuum processing chamber 10 whose inside is maintained at a high vacuum to perform an etching process on a wafer 50 of an object to be processed; a lower electrode 20, disposed at a lower portion of the vacuum processing chamber 10, that also serves as a mounting table for mounting thereon the wafer 50; an upper electrode 40 disposed opposite to the lower electrode 20 in the vacuum processing chamber 10; and a heat exchanger 15 provided at an inner wall of the vacuum processing chamber 10. The lower electrode 20 is connected to a high frequency power supply 25 through a blocking capacitor 22 and a high frequency matching circuit 21; and the upper electrode 40 has gas injection openings 42 for injecting a gas transferred from a gas feeding unit 41, which supplies a specific gas. Further, at the vacuum processing chamber 10, there are provided an gas introduction line 80 for introducing a gas thereinto; a vacuum exhaust port 12 connected to an exhaust means (not shown); and a pressure gauge 13 for measuring a pressure in the vacuum processing chamber 10 through a pressure gauge port 14.
In the aforementioned dry etching device, the vacuum processing chamber 10 is evacuatable by the exhaust means (not shown), and at the same time, a liquid or a gas is introduced into the vacuum processing chamber 10 through the gas introduction line 80. The introduced liquid or gas is cooled by adiabatic expansion, and is solidified or liquefied using a particle floating in the vacuum processing chamber 10 as a core, to fall to the lower portion of the vacuum processing chamber 10. The particles grown with the solidification or the liquefaction adhere on the wafer 50, resulting in defects of etching or film formation.
Further, by recent studies on generation of contamination of an object to be processed due to particles, it has been known that particles, adhered on the inner wall of the processing chamber or the like in the processing apparatus for use in the manufacturing process of the object, peel off to adhere on the object, resulting in the contamination thereof. Moreover, it has been also known that if the inner wall of the processing chamber is heated to the temperature of 40° C. to 50° C. and an etching process is performed on the object, a large number of particles are generated inside the processing chamber, resulting in the contamination of the object (see, e.g., U.S. Pat. No. 6,024,105).
However, the problematic point is that a mechanism of contamination of an object to be processed due to the particles in the processing apparatus has not been studied enough to reduce the contamination of the object due to the particles.